88 



BEES AND BEE-KEEPING. 



it is to the strain of the leg and wing movements, 

 corrugations and plaitings, supplemented by internal 

 webs (see Plate I.), are provided, to give the needed 

 rigidity, just as the engineer secures the same by 

 corrugating his sheet iron, and adding webs to his 

 girders. Beside these, between the meso and meta- 

 thorax, lies a stiff extension — really a plate bone — 

 called the meso-phragma, to give solid attachment to 

 part of the muscles of the organs of flight. 



Fig. 13.— Longitudinal Section Through Head, just Outside Right 

 Antenna (Magnified Fourteen times). 



a, Antenna, with Three Muscles attached to rncp, Meso-cephalic Pillar ; cl, 

 Clypeus ; Ibr, Labrum, or Upper Lip ; No. 1, Chyle Gland (System No. 1 of 

 Siebold) ; this Gland really runs in front of the Meso-cephalic Pillars, but here 

 the latter are kept in view ; o, Opening of same ; oc, Ocellus, or Simple Eye ; 

 en, Cephalic Ganglion ; n, Neck ; th, Thorax ; os, OSsophagus ; sd 2, 3, Common 

 Salivary Ducts of Systems No. 2 and No. 3 ; sd 2 and sd 3, Salivary Ducts of 

 Systems No. 2 and No. 3 respectively ; sv, Salivary Valve ; c, Cardo ; ph. Pharynx ; 

 lb, Labium, or Lower Lip, with its Parts Separated for Display ; mt, Men'tum, 

 or Chin ; mx, Maxilla ; Ip, Ip, Labial Palpi ; I, ligula ; b, Bouton. 



In the head, which has to sustain the heavy pull of 

 the jaw and tongue muscles, besides defending the 

 brain and delicate glands, corrugation is prevented 

 by the presence of the very large compound eyes 

 with their essential regularity of outline, an element 

 of weakness, unless some device were introduced to 



